24vmic Audio CCTV Microphone for Security DVR Camera

Dongguan NVT co, Ltd, this company stay in shipai town, donggguan city, guandong prov. China.

Twisted pair video transmission using unshielded twisted pair (UTP: Unshielded twisted-pair) as the transmission medium, the use of differential transmission principle, the transmitter will be equal to the amplitude of the video signal is converted into a polar opposite of differential signals over twisted pair after the long haul, at the receiving end of two differential signals of opposite polarity subtraction becomes the usual video signals. Effectively suppress common mode interference, twisted pair can transmit clear images even under strong interference signal environment.

Applications in the areas of security, education and other high-definition AV signal transmission, capable of real-time transmission of color or monochrome PAL, NTSC, SECAM and other baseband video signal standard, has anti-interference ability, long transmission distance, wiring easy, inexpensive, and many advantage

Second, the application characteristics

1. Transmission distance, high image quality. Since twisted pair transmitter uses advanced processing technology, the video signal amplitude and different frequency attenuation amplification and compensation, maintaining the original video luminance and chrominance signals and real-time, even in the long-distance transmission almost no distortion.

2. Easy wiring, cable high utilization. One pair of ordinary telephone lines can be used to transmit video signals. Another widely laying the building within a building Category 5 unshielded twisted pair taken any way you can transmit video signals without additional wiring, even re-wiring, Category 5 twisted pair is also easier than coaxial cable. In addition, within a Category 5 twisted pair has four pairs of twisted pair, if you use a pair of lines to transmit video signals, in addition to a few of the lines can also be used to transmit audio signals, control signals, power supply or other signals, improved cable utilization while avoiding the hassle of wiring to separate the various signals, reducing the project cost.

3 anti-interference ability. Twisted pair can effectively suppress common mode interference, even in noisy environments, twisted pair can also send excellent image signal. Several pairs of twisted pair cable to send different signals, respectively, the interference will not occur between them.

4 high reliability and ease of use. The use of twisted-pair transmission of video signals in front to access special transmitter in the control center to access a dedicated receiver. This inexpensive twisted-pair transmission equipment, is also very simple, without too much expertise and no action, once installed, the long-term stability.

5 DC 12-24V wide voltage input range, improved transient suppression protection.

1, DMV series transmitters are what cable choice?

Recommend the use of five or more than five standard unshielded twisted pair (core diameter 0.51mm), can achieve the best video transmission. Note that if you use shielded twisted pair including RJ45 crystal head must also be shielded to ensure that the entire shield twisted pair, RJ45 and RJ45 interface shell crystal head form a good ground, otherwise it will generate an internal self-interference.

Special Note: Technical standards every five twisted-pair wire core DC loop resistance of 100 meters for the 18-19Ω (single resistor is about 100 meters 9Ω ), the DC resistance of substandard products would exceed the lot, use of substandard UTP will seriously affect the transmission performance and distance.

2, DMV series transmitter with RJ11 telephone line can transmit it?

DMV video transmission using RJ11 telephone lines to transmit video, can reduce the cost of the wire, but the image RJ11 telephone line susceptible to interference, will shorten the transmission distance.